<html>
  <head>
    <style>
      #ui {
        display: flex;
        flex-direction: column;
        width: 20em;
        padding: 1em;
        background-color: rgb(250, 250, 250);
        border-radius: 1em;
      }

      button {
        flex: 1;
        margin: 0.2em;
        height: 2em;
      }

      #dot {
        background-color: rgb(240, 240, 240);
        width: 2em;
        height: 2em;
        border-radius: 50%;
        animation: none;
        margin: 0.2em;
      }

      #rtf-div {
        margin: 0.2em;
        width: 3em;
        text-align: center;
        vertical-align: middle;
        height: 2em;
        line-height: 2em;
        border-radius: 20vh;
        background-color: rgb(240, 240, 240);
        color: white;
      }

      #link-background {
        background-color: rgb(252, 176, 62);
        padding-top: 0.2em;
        padding-bottom: 0.2em;
        padding-right: 1em;
        padding-left: 1em;
        font-family: Arial;
        margin-left: 1em;
        margin-right: 1em;
      }

      #outputs,
      #buttons {
        display: flex;
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
      }

      #progress-bar-background,
      #rms-meter-background {
        background-color: rgb(240, 240, 240);
        flex: 1;
        margin: 0.2em;
        height: 2em;
      }

      #rms-meter-background {
        height: 0.5em;
      }

      #progress-bar-value,
      #rms-meter-value {
        background-color: green;
        height: 100%;
        width: 0%;
        animation: none;
      }

      @keyframes progress {
        0% {
          width: 0%;
        }
        100% {
          width: 100%;
        }
      }

      @keyframes blinker {
        0% {
          background-color: orange;
        }
        50% {
          background-color: red;
        }
        100% {
          background-color: orange;
        }
      }
    </style>
  </head>

  <body>
    <div id="ui">
      <div id="buttons">
        <button type="button" id="start_button" disabled="true">start</button>
        <button type="button" id="stop_button" disabled="true">stop</button>
      </div>
      <div id="outputs"></div>
    </div>
  </body>
</html>
